1. Field of the Invention:
This invention relates to a method for excavating a hole in the ground and an apparatus therefor and, more particularly, to a method and an apparatus suitable for the operation of excavating a hole used for laying a lateral sewer or mounting pipe, which extends from a main sewer pipe toward the surface of the ground, on the main sewer pipe.
2. Description of the Prior Art:
One method for laying a branch pipe or mounting pipe for sewage the comprises the steps of excavating a ditch by the open cut method, positioning the mounting pipe in the excavated ditch and then connecting the mounting pipe to a main pipe provided in the ground. The method noted above, however, cannot be applied to locations which cannot be excavated by the open cut method.
A different method for laying a sewage mounting pipe comprises the steps of excavating a hole from the ground surface to the main pipe by an excavating machine such as an earth auger and then positioning the mounting pipe in the hole. According to this method, however, the hole is formed by excavating the ground from the ground surface to the main pipe provided in the ground, so that the tip of the excavated hole often deviates from the position where the main pipe is embedded and, as a result, the mounting pipe cannot be accurately laid.